The dealers do it (at least the one in Oakland does, call Stead to see) and then you don't have to teach them how to get to the engine compartment. If you end up going to an independent station, help them. They will need you to open the cover off the engine in the same way you do it for a filter change.

I had my check done at a regular smog checker. Apparently the only need to view the engine is to check if any modifications were done. The business I used trusted that I had no reason to beef up my car and skipped that step.